xlistview的（java）

package com.bwie.xlistviews;

import java.text.SimpleDateFormat;
import java.util.Date;

import com.bwie.test.R;

import android.annotation.SuppressLint;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.view.animation.DecelerateInterpolator;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Scroller;
import android.widget.TextView;
public class XListView extends ListView implements OnScrollListener {
private float mLastY = -1; // save event y
private Scroller mScroller; // 用于回滚
private OnScrollListener mScrollListener; // 回滚监听
// 触发刷新和加载更多接口.
private IXListViewListener mListViewListener;
// -- 头部的View
private XListViewHeader mHeaderView;
// 查看头部的内容，用它计算头部高度，和隐藏它
// 当禁用的时候刷新
private RelativeLayout mHeaderViewContent;
private TextView mHeaderTimeView;
private int mHeaderViewHeight; // 头部View的高
private boolean mEnablePullRefresh = true;
private boolean mPullRefreshing = false; // 是否刷新.
// -- 底部的View
private XListViewFooter mFooterView;
private boolean mEnablePullLoad;
private boolean mPullLoading;
private boolean mIsFooterReady = false;
// 总列表项，用于检测列表视图的底部
private int mTotalItemCount;

// for mScroller, 滚动页眉或者页脚
private int mScrollBack;
private final static int SCROLLBACK_HEADER = 0;// 顶部
private final static int SCROLLBACK_FOOTER = 1;// 下部

private final static int SCROLL_DURATION = 400; // 滚动回时间
private final static int PULL_LOAD_MORE_DELTA = 50; // 当大于50PX的时候，加载更多

private final static float OFFSET_RADIO = 1.8f; // support iOS like pull
// feature.

/**
* @param context
*/
public XListView(Context context) {
super(context);
initWithContext(context);
}

public XListView(Context context, AttributeSet attrs) {
super(context, attrs);
initWithContext(context);
}

public XListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initWithContext(context);
}

private void initWithContext(Context context) {
mScroller = new Scroller(context, new DecelerateInterpolator());
// XListView need the scroll event, and it will dispatch the event to
// user's listener (as a proxy).
super.setOnScrollListener(this);

// 初始化头部View
mHeaderView = new XListViewHeader(context);
mHeaderViewContent = (RelativeLayout) mHeaderView
.findViewById(R.id.xlistview_header_content);
mHeaderTimeView = (TextView) mHeaderView
.findViewById(R.id.xlistview_header_time);
addHeaderView(mHeaderView);// 把头部这个视图添加进去

// 初始化底部的View
mFooterView = new XListViewFooter(context);

// 初始化头部高度,通过全局布局改变事件的监听
mHeaderView.getViewTreeObserver().addOnGlobalLayoutListener(
new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {

mHeaderViewHeight = mHeaderViewContent.getHeight();
getViewTreeObserver()
.removeGlobalOnLayoutListener(this);
}
});
}

@Override
public void setAdapter(ListAdapter adapter) {
// 确定XListViewFooter是最后底部的View, 并且只有一次
if (mIsFooterReady == false) {
mIsFooterReady = true;
addFooterView(mFooterView);
}
super.setAdapter(adapter);
}

/**
* 启用或禁用下拉刷新功能.
*
* @param enable
*/
public void setPullRefreshEnable(boolean enable) {
mEnablePullRefresh = enable;
if (!mEnablePullRefresh) { // 禁用,隐藏内容
mHeaderViewContent.setVisibility(View.INVISIBLE);// 如果为false则隐藏下拉刷新功能
} else {
mHeaderViewContent.setVisibility(View.VISIBLE);// 否则就显示下拉刷新功能
}
}

/**
* 启用或禁用加载更多的功能.
*
* @param enable
*/
public void setPullLoadEnable(boolean enable) {
mEnablePullLoad = enable;
if (!mEnablePullLoad) {
mFooterView.hide();// 隐藏
mFooterView.setOnClickListener(null);
} else {
mPullLoading = false;
mFooterView.show();// 显示
mFooterView.setState(XListViewFooter.STATE_NORMAL);
// both "上拉" 和 "点击" 将调用加载更多.
mFooterView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
startLoadMore();
}
});
}
}

/**
* 停止刷新, 重置头视图.
*/
public void stopRefresh() {
if (mPullRefreshing == true) {
mPullRefreshing = false;
resetHeaderHeight();
}
}

/**
* stop load more, reset footer view.
*/
public void stopLoadMore() {
if (mPullLoading == true) {
mPullLoading = false;
mFooterView.setState(XListViewFooter.STATE_NORMAL);
}
}

/**
* 設置最後一次刷新時間
*
* @param time
*/
@SuppressLint("SimpleDateFormat")
public void setRefreshTime(String time) {
SimpleDateFormat   formatter   =   new   SimpleDateFormat   ("yyyy年MM月dd日   HH:mm:ss     ");
Date   curDate   =   new   Date(System.currentTimeMillis());
//获取当前时间
String   str   =   formatter.format(curDate);
mHeaderTimeView.setText(str);
}

private void invokeOnScrolling() {
if (mScrollListener instanceof OnXScrollListener) {
OnXScrollListener l = (OnXScrollListener) mScrollListener;
l.onXScrolling(this);
}
}

private void updateHeaderHeight(float delta) {
mHeaderView.setVisiableHeight((int) delta+ mHeaderView.getVisiableHeight());
if (mEnablePullRefresh && !mPullRefreshing) { // 未处于刷新状态，更新箭头
if (mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
mHeaderView.setState(XListViewHeader.STATE_READY);
} else {
mHeaderView.setState(XListViewHeader.STATE_NORMAL);
}
}
setSelection(0); // scroll to top each time
}

/**
* 重置头视图的高度
*/
private void resetHeaderHeight() {
int height = mHeaderView.getVisiableHeight();
if (height == 0) // 不显示.
return;
// 不显示刷新和标题的时候，什么都不显示
if (mPullRefreshing && height <= mHeaderViewHeight) {
return;
}
int finalHeight = 0; // 默认：滚动回头.
// 当滚动回显示所有头标题时候，刷新
if (mPullRefreshing && height > mHeaderViewHeight) {
finalHeight = mHeaderViewHeight;
}
mScrollBack = SCROLLBACK_HEADER;
mScroller.startScroll(0, height, 0, finalHeight - height,
SCROLL_DURATION);
// 触发刷新
invalidate();
}

// 改变底部视图高度
private void updateFooterHeight(float delta) {
int height = mFooterView.getBottomMargin() + (int) delta;
if (mEnablePullLoad && !mPullLoading) {
if (height > PULL_LOAD_MORE_DELTA) { // 高度足以调用加载更多
mFooterView.setState(XListViewFooter.STATE_READY);
} else {
mFooterView.setState(XListViewFooter.STATE_NORMAL);
}
}
mFooterView.setBottomMargin(height);

// setSelection(mTotalItemCount - 1); // scroll to bottom
}

private void resetFooterHeight() {
int bottomMargin = mFooterView.getBottomMargin();
if (bottomMargin > 0) {
mScrollBack = SCROLLBACK_FOOTER;
mScroller.startScroll(0, bottomMargin, 0, -bottomMargin,
SCROLL_DURATION);
invalidate();
}
}

// 开始加载更多
private void startLoadMore() {
mPullLoading = true;
mFooterView.setState(XListViewFooter.STATE_LOADING);
if (mListViewListener != null) {
mListViewListener.onLoadMore();
}
}

// 触发事件
@Override
public boolean onTouchEvent(MotionEvent ev) {
if (mLastY == -1) {
mLastY = ev.getRawY();
}

switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mLastY = ev.getRawY();
break;
case MotionEvent.ACTION_MOVE:
final float deltaY = ev.getRawY() - mLastY;
mLastY = ev.getRawY();
System.out.println("数据监测：" + getFirstVisiblePosition() + "---->"
+ getLastVisiblePosition());
if (getFirstVisiblePosition() == 0
&& (mHeaderView.getVisiableHeight() > 0 || deltaY > 0)) {
// 第一项显示,标题显示或拉下来.
updateHeaderHeight(deltaY / OFFSET_RADIO);
invokeOnScrolling();
} else if (getLastVisiblePosition() == mTotalItemCount - 1
&& (mFooterView.getBottomMargin() > 0 || deltaY < 0)) {
// 最后一页，已停止或者想拉起
updateFooterHeight(-deltaY / OFFSET_RADIO);
}
break;
default:
mLastY = -1; // 重置
if (getFirstVisiblePosition() == 0) {
// 调用刷新,如果头部视图高度大于设定高度。
if (mEnablePullRefresh
&& mHeaderView.getVisiableHeight() > mHeaderViewHeight) {
mPullRefreshing = true;// 那么刷新
mHeaderView.setState(XListViewHeader.STATE_REFRESHING);
if (mListViewListener != null) {
mListViewListener.onRefresh();
}
}
resetHeaderHeight();// 刷新完毕，重置头部高度，也就是返回上不
}
if (getLastVisiblePosition() == mTotalItemCount - 1) {
// 调用加载更多.
if (mEnablePullLoad
&& mFooterView.getBottomMargin() > PULL_LOAD_MORE_DELTA) {
startLoadMore();// 如果底部视图高度大于可以加载高度，那么就开始加载
}
resetFooterHeight();// 重置加载更多视图高度
}
break;
}
return super.onTouchEvent(ev);
}

@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
if (mScrollBack == SCROLLBACK_HEADER) {
mHeaderView.setVisiableHeight(mScroller.getCurrY());
} else {
mFooterView.setBottomMargin(mScroller.getCurrY());
}
postInvalidate();
invokeOnScrolling();
}
super.computeScroll();
}

@Override
public void setOnScrollListener(OnScrollListener l) {
mScrollListener = l;
}

@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
if (mScrollListener != null) {
mScrollListener.onScrollStateChanged(view, scrollState);
}
}

@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// 发送到用户的监听器
mTotalItemCount = totalItemCount;
if (mScrollListener != null) {
mScrollListener.onScroll(view, firstVisibleItem, visibleItemCount,
totalItemCount);
}
}

public void setXListViewListener(IXListViewListener l) {
mListViewListener = l;
}

/**
* 你可以监听到列表视图，OnScrollListener 或者这个. 他将会被调用 , 当头部或底部触发的时候
*/
public interface OnXScrollListener extends OnScrollListener {
public void onXScrolling(View view);
}

/**
* 实现这个接口来刷新/负载更多的事件
*/
public interface IXListViewListener {
public void onRefresh();

public void onLoadMore();
}
}